Improving the Quality of Care Provided Through Bundled Payments for Patients with Alzheimer's Disease or Other Forms of Dementia or Frailty: Abstract Post-acute care (PAC) after a hospitalization helps patients with poor functional status ? including the growing number of vulnerable older adults with Alzheimer's and other forms of dementia and/or frailty ? make a successful transition to home through rehabilitation services provided after discharge. PAC has been fastest- growing segment of Medicare spending prompting Medicare to increasingly transition to new payment models that create strong incentives to reduce PAC care. Bundled Payments for Care Improvement (BPCI) is a large, voluntary Medicare payment reform initiative that started in 2013. In BPCI's ?Model 3,? PAC providers caring for patients discharged with one or more of 48 targeted conditions assume responsibility for the entire cost of post-acute care over a 30, 60 or 90- day period subsequent to hospital discharge and PAC admission, including any readmissions, emergency care or outpatient visits. Episodes can be initiated by transfer of care from a hospital to a skilled nursing facility (SNF), home health agency, rehabilitation hospital, or long-term care hospital. As of July 2017, 1143 episode initiating organizations were participating in BPCI, of which 76% were SNFs. If Medicare payments are lower than historical costs of care, enrollees are able to keep a portion of the savings; if Medicare payments exceed the target enrollee will be responsible for part of the overage. Bundled payments provide strong incentives for PAC providers to better-coordinate services and redesign care, which could be very helpful for vulnerable older adults On the other hand, such programs could also induce providers to skimp on care or avoid these patients. Determining the true impact of payment reforms like BPCI requires evaluating both (1) how PAC providers redesign care to achieve better outcomes and lower costs, and (2) whether they skimp on care or reduce access for high need patients. We plan to: 1) use administrative to determine whether BPCI was associated with worsening access to care and clinical outcomes for patients with dementia and/or frailty; 2) use a national survey of SNFs to determine the strategies used by BPCI participants to redesign care for patients with dementia and/or frailty; and 3) combine these two data sources to determine if any specific strategies for care redesign are associated with improvements in outcomes for patients with dementia and/or frailty. This combined evidence will meaningfully advance our understanding of how to design policies to incentivize the delivery of high-quality, cost-effective PAC to vulnerable older adults and avoid unintended negative consequences.